Understanding cell division ultimately requires a comprehensive view of the essential events that occur and the regulatory pathways that control them. While chromosome segregation is a defining feature of division, other compartments of the cell must also be carefully divided into daughter cells, and coordinated with progress through the division process. Membrane trafficking is shut down during metaphase, and resumes during late anaphase. The cell cycle signals regulating this transition are incompletely understood. Separase is a key protease that cleaves the glue holding sister chromatids together to allow chromosome separation at the onset of anaphase. Separase also has additional functions during late anaphase to promote the final events in cell division including the regulation of vesicle trafficking. This proposal describes research aimed at understanding how separase mediates vesicle trafficking events in collaboration with other closely related cell cycle regulators that have well characterized roles in chromosome segregation. Separase localizes to vesicles and is required for exocytosis. We will define the domain of separase required for vesicle localization and how vesicle localization is regulated. We will also investigate the mechanism by which separase promotes exocytosis, whether the protease activity is required, and seek new effectors that separase acts upon to trigger exocytosis. These studies will be performed using the genetically tractable C. elegans embryo supplemented by biochemical approaches with Xenopus laevis egg extracts. This work will provide new insight into how cells coordinate the essential process of chromosome segregation with other events that must occur for accurate division, which is relevant to understanding normal development and diseases such as infertility and cancer.